Indeed. I don't understand why a SRD-7 Pro works but not a Mk2 since they are essentially identical.

protecting yourself from lawsuit? If you're telling the truth and are providing documenting photographs, it's hard to believe there'd be grounds for a lawsuit.

Unfortunately telling the truth is not good enough. Companies who have fired someone can't even tell that person's prospective new employer why he/she was fired (theft, etc) even if it's the truth and 100% provable, because it interferes with them being able to get a new job. This is the same thing as it interferes with the seller being able to conduct trade. Nice BS laws we have in this country.

Unfortunately telling the truth is not good enough. Companies who have fired someone can't even tell that person's prospective new employer why he/she was fired (theft, etc) even if it's the truth and 100% provable, because it interferes with them being able to get a new job. This is the same thing as it interferes with the seller being able to conduct trade. Nice BS laws we have in this country.

But they are a heavily inductive load, and that definitely pisses off some power amps.

Interesting - is that why the SRD-7 Spritzer (and pre-Spritzer) hums with an Audio Research amp amd not with a Studer amp?

Interesting - is that why the SRD-7 Spritzer (and pre-Spritzer) hums with an Audio Research amp amd not with a Studer amp?

The other problem is that some amps have a bit of background hum thats hard to notice with speakers, but really is

noticable with a transformer box. My ARC vt60 (tubes) has this issue. 20 year old tube amps would take a lot of work

to rid yourself of any hum. I have since splurged for some Stax energizers. Problem solved.

I had an old H/K receiver from about 1980 that worked great, also used a Rotel rb980 SS amp that worked well.

The hum can be either the bias supply's lack of a transformer causing hum or just residual hum in the amp. Older amps. especially tube amps, are very prone to hum. AC heater wiring just adds to this issue.

Now I remember, Birgir - you mentioned the transformer solution in the past. Sorry, old brain!

Spritzer or anybody else havng already done this,

when implementing the BIAS for the stax daphragm, you need to set one resistor connected between each stator and bias 0V to have the ias voltage betwen the diaphragm and the stator (e.g. 10Mohm). Do you still need an extra resistor (5Mohm has been suggested) in series with the bias voltage and the diaphragm in this case?

Apologies if I'm getting this completely wrong but, how they say, if you don't ask you will be stupid for ever.

Thanks.

I wouldn't bother with those resistors and keep the 5M resistor as well. It costs nothing and if something goes horribly wrong it will kill most of the bias voltage.

I would place output resistors (5K1) if you want extra protection but there is no need for the 10M units.

Mmh... not sure I understand how the whole thing works then. We need 580V between the diaphragm and each stator. To do this we need to connect the diapraghm to the +580V and the stator to the 0V. As we have two stators they will be both connected together to the bias 0V shortcutting the signal output.

I'm using a tube PP amp plugging the stator to the OPT primary connections.

I'm going to duoble the 300ACV from the B+ tranformer and use it as bias.

This is why I thought it was necessary to have the two 10mohm resistors to separate the two stators, still providing a ground rference for the bias, and was puzzled only about the extra 5Mohm resistor between Bias V+ and diaphragm you seem to suggest for security reason.

To give an example please have a look at the secodn schematic in the auridux page: http://dddac.de/tp08.htm The only difference in my case is that I can't take the bias from the B+ as it is too low and need to source it via a doubler.

Thanks.

The output on the stators is AC but the polarizing voltage is DC. The only thing the bias does is to set the potential of the diaphragm so it can be pushed and pulled by the AC voltage on the stators. The ballast resistor for the bias supply is used to set the diaphragm to constant charge for lowest distortion but in reality it acts much more as a safety feature. The diaphragm is an open circuit in essence so if something were to close that circuit the ballast resistor would drop most of the voltage.

What you are doing is something rather different and those 10M resistors are used to balance out the output stage and to drain the output caps.

Staxusa.com (Yama's) has brown arcs apparently. They didn't reply to my email but I ordered a pair expecting black but got brown.

All fixed:

Edited March 9, 201214 yr by Maxvla

congrats!

Staxusa.com (Yama's) has brown arcs apparently. They didn't reply to my email but I ordered a pair expecting black but got brown.

All fixed:

So, how much was the total damage for the phones and new parts?

All said and done, $1755. Not the best deal, but not bad. The mint pairs on Audiogon go for around $1750-1850, and with new leathers and a body that is free from any dings or dents, this one is nearly mint condition now. I cleaned out any hairs or dust from the driver area while I had the pads off.

Not a bad price at given how much people are willing to pay for fubar sets.

As if there was ever any doubt but the 007 Mk1 sounds great with the KGSSHV.

Bit the bullet and sealed the deal on these - Mint MK1’s S/N 70060

I saw those on Canuck Audio Mart the other day. Nice buy!

Bit the bullet and sealed the deal on these - Mint MK1’s S/N 70060

Nice!

Are you building a KGSSHV to pair with them?

Thanks guys! They’ll be sitting on the shelf for a while before I can finish my KGSSHV...

EDIT: n3rdling I just missed your post by a hair, I”m well into the build, I have a mass of parts in boxes and panels that are 95% complete as FPE files ready to hand over to Cam-Expert for some wallet haemorrhaging.

Edited March 22, 201214 yr by johnwmclean

Do you have any stat amp you can use in the meantime?

I’ve got no rig in the meantime Monkey, all my dynamic rigs been sold off, kind of a limbo for a while at least.

I’ve got no rig in the meantime Monkey, all my dynamic rigs been sold off, kind of a limbo for a while at least.

Well, first of all, congrats, it looks like you got a great O2. Secondly, you might consider getting an SRM1/Mk2 or similar amp to listen through in the interim.

mmm...mint O2 mk1....